Mutchus

How to Build a Bipolar Power supply for Battery instruments . A bipolar power supply overcomes those limitations. Most importantly, it can provide both positive and negative voltages from a single pair of terminals. There are no relays to switch polarity, so a bipolar supply can move smoothly from positive, through zero, to negative voltages.   Bipolar Power supply for Battery instruments Circuit Diagram It also regulates zero volts or other very small voltages. In this Bipolar Power supply for Battery instruments circuit diagram to generate regulated ± 5-V supplies from a pair of dry batteries, the circuit of Fig. 1 is commonly used. In order to give protection from inadvertent reverse connection of a battery, a diode in series with each battery would produce an unacceptable voltage drop.  The more effective approach is to fit diodes Dl and D2 as shown in Fig. 2, in parallel with each battery. When the supply is switched off, there is the risk of a reverse bias being ...

Here is the circuit diagram of a battery level indicator .This circuit is very simple and very cheap and compact.It can be used in transistor one band,two band or three band.This circuit is also used in emergency lights and other power supply circuits. Battery levels,normal or are indicated by the green or red LED repectively.One can set the circuit for monitoring the level of the battery within 3 to 10V with the help of 10k preset. Transistor T1 is 'ON' due to the voltage divider biasing.Green LED is 'ON' as the collector of T1 is almost at ground. When voltgae drops below the preset voltage,T1 switches off as the voltage is not sufficient to bias it to "ON" state.But the voltage at the base of T2 is sufficient to switch on T2 to conduction. Thus red LED glows-indicating the under voltage state of the battery

Normally, chargers available in the market do not have any sort of control except for a ro-tary switch that can select different tap-pings on a rheostat, to vary the charging current. This type of control is not adequate because of the irregular fluctuations in the mains supply, rendering the control ineffective.  A simple circuit intended for automatic charging of lead-acid batteries is presented here. It is flexible enough to be used for large capacity inverter batteries. Only the rating of transformer and power transistor needs to be increased. Circuit diagram : Automatic Battery Charger Circuit Diagram   The circuit has been basically designed for a car battery (about 40 Ah rating), which could be used for lighting two 40W tube lights. The circuit includes Schmitt trigger relay driver,float charger,and battery voltage monitor sections.  The Schmitt trigger is incorporated to avoid relay chattering. It is designed for a window of about 1V. During charging, when the ...

The LM317 is AN adjustable three terminal transformer that is capable of supply 1.2 to 37 volts with a secure 1.5A output current. The LM317 is prepackaged terribly} normal electronic transistor package that makes it very simple to mount in your circuits. Schematic Overview The LM317 series of adjustable 3-terminal positive voltage regulators is capable of supply in more than 1.5A over a 1.2V to 37V output vary. they're exceptionally simple to use and need solely 2 external resistors to line the output voltage. Further, each line and cargo regulation square measure higher than normal mounted regulators. In addition to higher performance than mounted regulators, the LM317 series offers full overload protection out there solely in IC's. enclosed on the chip square measure current limit, thermal overload protection and safe space protection. The LM317 makes AN particularly easy adjustable change regulator, a programmable output regulator, or by connecting a set electrical d...

This small circuit was developed to monitor the battery in a model hovercraft. The lift in the model is produced by an electric motor driving a fan. To avoid the possibility of discharging the rechargeable battery pack too deeply, the design lights a conspicuous LED mounted on the model when a preset threshold voltage is reached. The circuit only uses a few components, which helps keep the total weight of the model down. The circuit connects to the model only across the two points where the voltage to be monitored can be measured. These also supply power to the circuit. The best place to connect the circuit is not at the battery terminals, but rather at the motor connections. The circuit is suitable for use with nominal battery voltages of 4.8 V to 9.6 V (four to eight 1.2 V cells). For example, if there are six cells in the battery, its nominal terminal voltage will be 7.2 V. A discharge threshold voltage of around 1 V per cell is appropriate, which means that for six cells the thresh...

Normally, chargers available in the market do not have any sort of control except for a ro-tary switch that can select different tap-pings on a rheostat, to vary the charging current. This type of control is not adequate because of the irregular fluctuations in the mains supply, rendering the control ineffective.  A simple circuit intended for automatic charging of lead-acid batteries is presented here. It is flexible enough to be used for large capacity inverter batteries. Only the rating of transformer and power transistor needs to be increased. Circuit diagram :   Automatic Battery Charger Circuit Diagram   The circuit has been basically designed for a car battery (about 40 Ah rating), which could be used for lighting two 40W tube lights. The circuit includes Schmitt trigger relay driver,float charger,and battery voltage monitor sections.  The Schmitt trigger is incorporated to avoid relay chattering. It is designed for a window of about 1V. During charging, wh...

Signals when an on-circuit battery is exhausted 5V to 12V operating voltage A Battery-status Indicator circuit can be useful, mainly to monitor portable Test-gear instruments and similar devices. LED D1 flashes to attire the user's attention, signaling that the circuit is running, so it will not be left on by mistake. The circuit generates about two LED flashes per second, but the mean current drawing will be about 200µA. Transistors Q1 and Q2 are wired as an uncommon complementary astable multivibrator: both are off 99% of the time, saturating only when the LED illuminates, thus contributing to keep very low current consumption. Circuit diagram : Flashing-LED Battery-status Indicator Circuit Diagram The circuit will work with battery supply voltages in the 5 - 12V range and the LED flashing can be stopped at the desired battery voltage (comprised in the 4.8 - 9V value) by adjusting Trimmer R4. This range can be modified by changing R3 and/or R4 value slightly. When the batt...